This invention relates generally to gas turbine engines, and more particularly, to methods and systems for controlling the operation of gas turbine engines.
At least some known gas turbine engines include a compressor section, a combustor section, and at least one turbine section. The compressor compresses air, which is mixed with fuel and channeled to the combustor. The mixture is then ignited generating hot combustion gases. The combustion gases are channeled to the turbine which extracts energy from the combustion gases for powering the compressor, as well as producing useful work to power a load, such as an electrical generator, or to propel an aircraft in flight.
To start the engine, it is rotated to a predetermined speed, fuel is introduced, and an ignitor is energized. Sometimes the gas turbine engine fails to start properly, and/or the flame in the gas turbine engine may be inadvertently extinguished. In either case, some liquid fuel, which is not burned, may remain in the gas turbine engine. In addition, when an engine is shutdown, it is possible for some of the fuel supplied to the engine to remain unburned and accumulate in low-points in the engine. However, unburned accumulated fuel within the engine may pose a hazard during subsequent starting of the gas turbine engine, because the left-over unburned fuel may ignite with the fuel supplied to the combustor during engine starting, thus providing an excessive amount of energy to the combustor and other parts of the gas turbine engine that may result in damage to such components.